let a = 1.1, b = 2;
let s = "baichen";
let j = true;
let o = {
    name: "baichen",
    age: 18,
    money: 0,
    f: function(a, b){
        return a - b;
    },
    nums: [1, 2, 3],
    obj: {
        c: 1,
        d: 2
    },
}
let n = null, y = [1, 2, 4];
let un;

o["title"] = "master";

function Print(){
    console.log(typeof(o), typeof(n), typeof(un));

    for (let key in o) console.log(`${key}: ${o[key]}`)
    console.log(o);
    // let ss = s.substr(0, 2) + "l" + s.substr(3);
    // console.log(ss); 
}

export {
    Print
}